Configuration Manager Client Upgrade Package Distribution Failed

Whenever you setup a new distribution point, the system will automatically distribute 2 packages to the distribution point.
1. Configuration Manager Client Package
2. Configuration Manager Client Upgrade Package

But somehow the Configuration Manager Client Upgrade Package failed to distribute to the distribution point. The upgrade package is hidden, hence unable to redistribute the upgrade package like normal package. Therefore, we have to trick the system to redistribute the packages.

Trick:
1. Open an empty notepad and save it as client.acu

2. Copy the client.acu to the inboxes\hman.box folder at the top-level site
3. Monitor the hman.log to check whether the Client Upgrade package gets updated